实现了四相步进电动机的正反转、急停等功能。为实现单片机控制步进电动机系统在数控机床上的特殊应用，系统设计了两个外部中断，以实现步进电动机在某段时间内的反复正反转功能，也即数控机床的刀架自动进给运动。-To achieve a four-phase stepper motor reversing, emergency stop and other functions. To achieve single-chip stepper motor control systems for special applications on CNC machine tools, system design, two external interrupts, in order to achieve a stepper motor repeatedly reversing function within a certain period of time, that is automatic turret CNC machine tools to the motion.